But while this happy little boy is something of a medical miracle, the fact that he is here at all is amazing too as 31-year-old mum Louise was told she only had a 7pc chance of ever getting pregnant.

When she was 11 years old she was diagnosed with type 1 diabetes, which means her body is unable to produce insulin, which leads to increased blood glucose levels and can be dangerous.

“I was well-behaved at first but then I started to misbehave and I didn’t look after myself,” said Louise, who lives with husband Jason, 29, off Dereham Road in Norwich.

At 23 she discovered she had kidney failure but she was eventually able to receive a kidney and pancreas transplant which she hoped would substantially improve her quality of life.

“After the transplant everything was normal, we even went to Greece on holiday but things changed very quickly,” said Louise, who met Jason via her best friend.

Just 18 months after the transplant her new kidney stopped working and she had to have it removed and once again start the lifesaving process of dialysis.

The subject of having children was not something the couple even thought about let alone discussed with such a low probability – but in 2009 Louise and Jason received the surprise news that she was pregnant.

“It was a complete shock but I miscarried a week later so it came and then it went,” she said.

“Being a woman, it’s natural to want to have a baby. A need took over and I figured as long as I looked after myself I would be OK.”

Eight months later there was another shock when they discovered there was not just one baby but two.

“I had a scan at five weeks and I discovered I was pregnant with twins.

“It didn’t run in either of our families so it was quite a shock,” added Louise.

She reports her health was probably the best it had ever been during the pregnancy, despite having dialysis five times a week, but sadly when she was 21 weeks pregnant in 2010 her twin girls were born too early.

Olivia was stillborn and Phoebe had a heartbeat, although she was not breathing.

“She passed with us,” said Jason, a raising achievement manager at the Ormiston Victory Academy in Costessey.

“My mum and two of my sisters were able to come.

“We were able to hold them and spend the night with them before we came home,” added Louise.

The girls are buried in a special spot at Colney Church.

After such a trauma, getting pregnant again was not on their minds although the couple felt they would like to try again eventually, perhaps if Louise was fortunate enough to have another transplant.

Yet nine months later Louise amazingly discovered she was pregnant for the third time and although doctors were worried, the family said they provided fantastic support – almost becoming friends instead of doctors and nurses.

It was during a normal scan that doctors found there was a problem with blood flow to the baby who was just 26 weeks.

“I felt if I could just make it to 28 weeks it would be more viable – before that it was touch and go,” said Louise.

Unfortunately, the doctors felt the situation was too dangerous to wait any longer and so baby Oscar was born by caesarean on November 19, 2011 – three months early.

“I was still having dialysis and then going to spend the rest of the day with him. There wasn’t a day for three months that we weren’t with him.”

By the end of his stay at the Norfolk and Norwich University Hospital, the couple were sleeping there at weekends to be close to their tiny boy.

Through the love and care of the staff as well as the fact he was a fighter, Oscar was allowed home on his due date of February 17, 2012.

Jason said it was very hard at first.

“There was no safety blanket, if something went wrong at the hospital there were doctors and nurses there. At home it was just us.”

But as time went by things improved and now Oscar is a happy and healthy 15-month-old.

“He is spot on for a one-year-old, which is what he would be if he was born on time.

“Being a lazy boy he isn’t interested in walking yet,” said Louise.

As a result of being born so early, Oscar has chronic lung disease. This should clear up as he gets older, but he might still be prone to asthma.

Louise says that when Oscar is old enough she will tell him about his sisters as well as his own story.

“I take him to the cemetery but obviously he is too young to understand at the moment. We have a photograph of them in the living room so they are not forgotten.”

Louise, who has recently recovered from a broken foot, is still waiting for a transplant but she appears to take it all in her stride.

She still has dialysis but does so from 5pm to 10pm three days a week so that she can look after Oscar during the day and Jason can take over at night.

“I wouldn’t advise anyone on dialysis to go out and get pregnant but it was worth it for us,” she said.